i was working on taking off the center member so i could replace my rear motor mount with an energy suspension one (replaced the front mount last week without taking off the center member)
one of the four bolts broke
the bolt didnt break off, but i am guessing that the nut that is welded to the part the bolt goes through broke off, and that nut is stuck on the bolt. so the bolt spins freely, and i cannot tighten of loosen it.


so is it still safe to drive, conservatively obviously, or should i just wait till monday and drive it into nissan to have them fix it.

 

You should be fine. I was doing the same job and found one of the front crossmember bolts was stripped when I removed it. I drove like that for a few days till Nissan could get a new bolt in.

With the nut being in there still I wouldn't worry at all. I might cancel plans to take it to the drag strip but for regular driving it's fine.

That bolt is most likely a special order piece. The fronts and rears are different but they are special pieces. I've replaced the front twice and no Nissan or Infiniti dealer in my area stocked it. You might want to order one before you take it in so you won't be without your car. They might not even need it but they're only a couple dollars. Cheap insurance compared to being without your car for several days.

If the parts guy has trouble finding the bolt in the computer have him look for motor mount bolts. The first time I ordered one the guy was looking under crossmembers or something like that.

 

thanks for the info. im glad im not the only one who has had this problem

 

a little update with my problem for future org references.
i was at the dealership this morning and after talking with the master mechanic i am going to have to leave the bolt the way it is and fix it later.
all the lower control arm bolts (numbered in pic) along with the engine support member are connected into a suspention piece, that piece would have to be completely replaced to solve my problem.


the alternative is to plasma cut out the section where the nut is welded to, weld a new nut onto a new piece of steel, then weld that nut/steel piece back onto the part.
im really dissapointed that it came down to this, but the mechanic and his son have a custom car fabricating business in my area so i could have them fix it and do other small repairs for 1/4 of the price of all the new parts/service at nissan. thats the only upside

 

That's too bad. The job doesn't look too complicated though. If you could pull it apart and bring the piece to a welding/fabrication shop it probably wouldn't be too expensive. You could do the motor mount install at the same time. The same shop could press out the old ones and press in the new ones.

 

You have to replace the sub-frame huh?

 

thanks for the pix man. I was looking for the same pix lately.

 

I wouldn't go to the dealer... you can drill the old one out.

You can probably find a grade 8 bolt at a hardware shop, same length and slightly bigger then just tap the hole to match the new bolt.



I can't imagine the dealer doing this and keeping it affordable.

 

when the mechanic had it up in the air, i asked him what all would have to come off to get the front sub-frame out, and he went over all the things i had thought of already. my only problem is time cause i start school soon, and i dont want to start trying to take off more items that just break on me, then i would get really screwed
i am not planning on having the dealer fix it, i would have a shop repair it. possibly the mechanic i talked to, because him and his son do custom car work.
the problem with drilling the bolt out is that it is spinning freely.
also it isnt a matter of just tapping a hole. there is a nut that is welded onto the front sub-frame (in a non-accessible spot), and that nut broke off of the subframe but is still attached to the bolt, causing my problem.

the good thing is that the mechanic was quite confident that the integrity of the car is not harmed at all. this will probably be something i get fixed this coming spring, so stay tuned...

 

well things worked out differently, found a good deal at a junkyard, and i started the replacement today. i got the old one off and here are the pics. (i forgot a before pic, but just take off your wheels and you get the idea)




here is the one i took off

close up of the pesky bolt that i get to cut out tomorrow

here is my replacement one, i cleaned up the rest pretty well and will repaint it.

what i did:
1. removed y-pipe
2. removed straight pipe
3. removed sway bar bolts (4)
4. removed power steering shield and bolts (3 on shield and 4 for the PS)
5. removed lower control arm bolts (12)
6. disconnected the 5spd shifter arms and bent back heat shield (4 bolts)
7. dropped out the subframe/engine mount beam (4 bolts subframe and could only get 3 off on the other cause one is stuck in as pictured above)

it just took awhile (5 hours), cause i had hand tools only, nothing broke fortunately, and i will get it back in tomorrow.

 

Nice, it's always a good feeling when you can fix it yourself.

Why are you cutting out the old bolt?

 

well the nut the bolt goes through broke off the subframe, but is still attached to the bolt. the nut is inside the subframe, and there is no way to access it. so cutting it is the only way to separate the subframe and the engine mount beam (whatever it is called)

 

Great work. I'd take longer because I'm scrawny and I can't lift heavy stuff.

 

Now I see. Good luck with it.

 

well i finished it about an hours ago, drove it around, no problems.

finally got the second motor mount in


covered the piece with 3M Rubberized Undercoating (except where the ypipe ran past)


here is my ghetto press for the mounts, 2 pieces of treated lumber and a bolt/nut + some common sense


here is the piece being lifted back into place. took about 5 hours from this point on to finish


in retrospect i would never do this again without power tools. i would help someone if they had a similar problem.
i also with i had a set of taps to run through each of the nuts on the new subframe piece before i set it back on the car, just to make things easier.

cya